Apparatus for holding glass plate during tempering



Dec. 1, 1936.

L. J B. FORBES APPARATUS FOR HOLDING GLASS PLATE DURING TEMPERING Filed June 5, 1935 F/GJ.

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Patented Dec. 1, 1936 UNITED STATES APPARATUS FOR HOLDING GLASS PLATE DURING'TEMPERING Lewis Jex-Blake Forbes, St. Helens, England, as-

signor ,to The American Securit Company, Wilmington, Del., a company of Delaware Application June 3, 1935, Serial No. 24,729

In Qreat Britain June 8, 1934 8 Claims. (Cl. 491-14) This invention relates to the tempering of glass plates and has for its object an improved method and apparatus for holding the plates during the operations.

Heretofore', the methods employed have been (1) to cut notches in the faces or edges of the plates and engage the notches by suspended hooks, (2) to grip the plate by its faces by tongs I having sharp points, and weightof the plate tending to close the tongs to cause thepoints to sided frame, provided with side clips to prevent lateral movement of the plate in the frame.

The first of these methods has the disadvantage of requiring a preliminary'operation for cutting the notches; the second has the disadvantage of making indentations in the faces of,the plate which, for many purposes; are unsightly; the

third method has. the disadvantage that the frame with side clips protects portions of the v plate from the tempering process.

' According to the'invention, the plate, is held by its edges only in such a way that anypressure applied edgewise of the plate does not cause the plate to buckle when soft and in such a way that all parts of the plate are exposed to the tempering process. 1

Two members, having projecting points or knife-edges, are so located that their projections engage the *twoopposite side edges respectively of the plate, and pressure is applied to the members. to cause them to grip theplate when cold and to cause their projections to enter the glass when heated -suiiiciently to become soft. Means are provided whereby the pressure between the pro-. jections and the glass is substantially released when the projections have entered the glass a predetermined distance, thus avoiding any.apressure between the two .edges of the glass sumcient to cause it to buckle when soft. Inthe accompanying drawing Figure 1 is a front elevation (with front pla removed) of a portion of one form of device according to the invention;

Figure 2 is a sectioz'r thereof through the line A--A of Figure 1; a

Figure 3 is a front elevation (with front plate removed) of another form, and I Figure 4 is a front elevation (partly broken away) of a third form.

Referring to Figures 1 and 2, the left top corner of the glass plate is shown at' I. On a sup-.

porting bar 2 there is adapted to1slide'a'carriage composed of upper and lower bars 3 and 4 re-- spectively to which are fixed plates 5, the front side plate being removed in Figure 1. The carriage 3, 4, 5 can be secured to the bar 2 in any position by the screw-6. A lever with depending arm I and horizontal arm 8 is pivoted to a pin 9 fixed-in the side plates 5. The arm I carries a 5 projectingipoint or knife-edge Ill, and the arm 8 carries a weight ll. The arm 8115 free to turn between an upper stop formed by the lower bar 4, at l2, and a lower stop IS. A similar carriage 3, 4, 5, with lever arms I, 8, facing the other 10' enter the glass, (3) to hold the plate in a threeway, is on the bar 2 located so that its projection II] is adapted to engage the right hand edge of the plate I. In operation, the two carriages '3,- 4, 5, are slid towards one another, withthe plate I between 5 them, until the two projections l0 bear against the two edges ofthe plate, while the arms 8 are against their upper stops l2. The carriages are thus secured to the bar} by the screws 6,. :I'he weight ll then maintainisfisufficient pressure of the projections" l0 on the edges of the glass plate ltohold'it. 'When,'in the process of tempering-"the plate I is heated, it reaches a temperature at which the weightsll are able to force the projections Ill into-the glass, until the arms'8, bear against their lower stops i3, This occurs before the plate has. become soft enough to buckle by the pressure on its'j'edges, and the continued yielding of the glass releases the pressure down to a negligible amount before the'plate can be buckled. i

Referring to Figure 3, which shows an alternaftive form of device, similar parts to those in Figures 1 and 2 are designated by the same refer- Alever withtarms l4 and I5 is r ence numbers. pivoted on a pin it fixedfin the side'pl'ates 5.

The arm l4 carries the projecting point orknifeedge l0, and the armgl-5 is forked so. as to present two'surfaces I1 andgl'B to thestop l9. When the surface I! is against the stop l9, as shown, the projection I0 is above thehorizontal through a the-pivoting pin l6. As in the first described form, there is a similar device adapted to engage a the right hand edge of the plate 1. v A

In operation, the carriages-3, 4, 5' are m'bved ,5

until the projections l0 bear against" oppositeedges of the plate, while the surfaces ,II are against the stops I9; Whenthe plate] is al- :lowed to hang between the projections --l;l l, the. friction between them and the glass tends to-turri eothe arms l4 downwards, and this increases; the pressure of theprojections I0 on the glass.

.When theplate softens sufficiently toallow the projections In to enter the glass, the arms 14 turn downwards until the surfaces l8 bear.against 55 the stops IS. The pressure between the projections is then substantially released.

Referring to Figure 4, which shows another form of the invention, the plate I is supported in a frame consisting of a bottom bar 20 and side members 2|. The bottom bar carries, at intervals, projecting points or knife-edges 22 on studs 23. The side members are composed of two bars 2|, pivoted to the bar 20, one on each side of it, at 24. At their upper ends, the side members 2| carry pins '25 by which they are suspended from the supporting bar 2 by loops 26 and hooks 21. Also engaging the pins 25 is a cross bar 28, the pins 25 entering slots 29 in the bar. A rod 30, having a projecting point or knife-edge I0, is adapted to slide in a bush between the two bars of each side member 2| and to be secured therein by the screw 3|.

In operation, the plate I is placed in the frame so that its bottom edge rests on the projections 22.: "I'he rods 30 are then moved inwards, so that their projections Ill bear against the glass, while the pins 25 of theiside members 2| are at the outer ends of the slots 29 in the cross bar 28. The rods 30 are then secured by the screws 3|, and the hooks 21 are then suspended from the bar 2 in such positions that they tend to draw the pins 25 of the side members towards one another.

When the plate becomes soft, this pressure tending to draw the side members towards one another causes the projections Hi to enter the edges of the glass plate I; until the pins 25 have reached the inner ends ofv the slots 29. The pressure is then taken by the cross bar 28, and is substantially released from the projections H).

The plate I sinks by its weight on to the projections 22, as the projections l enter its edges, so that the indentations made by the projections I0 become slightly elongated. This elongation may be avoided, if desired, in various ways, as for instance, by so constructing the bushes through which the rods 30 pass that they can turn in the side members 2|.

Having described my invention, I declare that what I claim and'desire to'secure by Letters Patent is:

1. Apparatus for holding a plate of glass for tempering comprising two, members having projectionsadapted to engage and enter the two opposite side edges respectively of the plate, means for applying pressure to the members to cause their projections to enter the glass when soft, and means for substantially releasing the pressure between the projections and the glass when the projections have entered the glass a predetermined distance.

2. Apparatus for holding a plate of glass for tempering comprising two supporting members adjustable-in respect of their distance apart, two members pivoted thereto respectively, having projections adaptedtoengage and enter the two opposite side edges respectively of the plate, means for applying pressure to the members to cause their projections to enter the glass when soft, and means for substantially releasing the pressure between the projections and the glass when the projections have entered the glass a predetermined distance.

3. Apparatus for-holding memlers pivoted thereto respectively, having projections adapted-to engage and enter the two a. plate oi? glass for 1 tempering comprising two supporting'members adjustable in respect of their distance apart, two

means for applying pressure to the members to cause their projections to enter the glass when soft, and a stop on each supporting member adapted to limit the movement of the pivoted member when its projection has entered the glass a predetermined distance.

4..Apparatus for holding a plate of glass for tempering comprising two supporting members adjustable in respect of their distance apart, two members pivoted thereto respectively, having projectionsadapted to engage and enter the two opposite side edges respectively of the plate, a weight attached to each pivoted member adapted to apply pressure to the member to cause its projection to enter the glass when soft, and means for substantially releasing the pressure between the projections and the glass when the projections have entered the glass a predetermined distance.

5. Apparatus for holding a plate of glass for tempering comprising two supporting members adjustable in respect of their distance apart, two members pivoted thereto respectively, having projections adapted to engage and enter the two opposite side edges respectively of the plate, a weight attached to each pivoted member adapted to apply pressure to the member to cause its projection to enter the glass when soft, and a stop on each supporting member adapted to limit the movement of the pivoted member when its projection has entered the glass a predetermined distance. 7

6. Apparatus for holding a plate of glass for tempering comprising two supporting members adjustable in respect of their distance apart, two members pivoted thereto respectively, having projections adapted to engage and enter the two opposite side edges respectively of the plate, two stops on each supporting member adapted to limit the movement of the pivoted member so that -members pivoted thereto having projections adapted to engage and enter the two opposite side edges respectively of the plate, means for applying pressure to the members to cause their projections to enter the glass. when soft, and means for substantially releasing the pressure between the projections and the glass when the projections havev entered the glass a predetermined distance.

8. Apparatus for holding a plate of glass for tempering, comprising a bottom member located below the plate, projections thereon adapted to engage the bottom edge of the plate, two side members pivoted thereto having projections adapted to engage and enter the two opposite side edges respectively of the plate, a support ing member above the plate, a suspending means between'each side member and the supporting bar, the points of attachment of the suspending means to the supporting bar being-closer to- I .gether. than their points of attachment to the side membersand means for substantiallyreleasingtheipressure between the projections and the glass wheni the projections have entered the. glass a predetermined distance.

LEWIS JEX-BLAKE FORBES. 

